Quantum Computer Performs Error-Resistant Operations with Logical Qubits
Harvard and QuEra make progress in error correction and perform operations on 48 logical qubits.
A Step Towards Error Correction
Error correction is a crucial step in the development of useful quantum computing. It involves distributing a logical qubit among multiple hardware qubits and is necessary to improve the accuracy of calculations.
A paper published in Nature details a significant milestone in this field. Researchers, primarily from Harvard University, have successfully performed operations on up to 48 logical qubits. The system, developed in collaboration with QuEra, can identify and correct errors, leading to more reliable results.
Yuval Boger, the Chief Marketing Officer of QuEra, expressed the significance of this achievement, stating that it brings us closer to the goal of large-scale, fault-tolerant quantum computers.
Catching and Fixing Errors
Quantum algorithms often require extensive manipulation of quantum information, which can result in errors when using hardware qubits. Error-correcting logical qubits are the solution to this problem. By distributing individual qubits among multiple hardware qubits, errors can be detected and corrected without losing all the information.
The addition of extra qubits enables error correction. These qubits are linked to the hardware qubits containing the logical qubits and are used to monitor their state and identify errors. By manipulating these extra qubits, the system can restore the lost information caused by errors.
Theoretically, error correction can significantly prolong the lifespan of quantum states compared to individual hardware qubits.
Challenges and Progress
Implementing error correction introduces additional complexity and requires a higher number of qubits. With each logical qubit needing several hardware qubits, the hardware requirements for running quantum algorithms increase. Full error correction also involves repeated measurements to identify, categorize, and correct errors, all while the logical qubits are in use.
While there are challenges, progress has been made in error-corrected qubits. They have shown better longevity for storing quantum information compared to hardware qubits. Some cases have even demonstrated the use of logical qubits for individual quantum operations. Companies like Atom Computing and IBM have increased their qubit counts to support larger numbers of logical qubits.
QuEra, a startup that originated from the same lab as Atom Computing, utilizes neutral atoms for their hardware. Neutral atom qubits offer stability in maintaining quantum information and the ability to move atoms, opening up more possibilities for linking qubits. The Harvard team relied on hardware similar to Atom Computing's for their research.
